New Chelsea boss Thomas Tuchel wants to transform their defence by shopping in Germany this summer.
BILD says Tuchel's appointment has seen Chelsea make a new move for departing Bayern Munich defender David Alaba.
Off contract in June, Alaba is understood to have committed to Real Madrid next season - though his father has insisted the Austria captain has not signed a pre-contract with anyone.
Along with Alaba, Tuchel is also keen on his Bayern teammate Niklas Sule.
Sule could be made available at Bayern this summer as they close in on a deal for RB Leipzig defender Dayot Upamecano.
